Planting and spraying systems have increasingly become more sophisticated and better able to handle the variety of applications presented by the agricultural industry. With this sophistication has come the need to further integrate the functions of planting and spraying control to provide a cost effective farm implement control environment.
Many farm implements are controlled by the operator of the agricultural vehicle to which the implements are attached or coupled. For example, planting and spraying systems have evolved for controlling and monitoring planting and spraying implements, respectively. These systems, however, have for the most part evolved separately.
Automated seed planters in planting systems usually include a plurality of seed feeders which serve as conduits for the seeds moving to the planting devices. Because seed feeders can become obstructed during planting, causing rows of crop land to be misplanted, planting systems use planter monitors to monitor the flow of seeds through the seed feeders and detect jams.
The first planter monitors used electromechanical switches to detect the passage of seeds through the seed feeders. Later systems used optical sensors for this purpose. A system for detecting the passage of seeds by monitoring changes in electrical fields caused by the movement through the field of objects with a high dielectric constant (such as seeds) was disclosed in Haase U.S. Pat. No. 4,710,757, the entire disclosure of which is hereby incorporated by reference. The Haase system uses sensors connected to a microcontroller to detect the passage of seeds.
A variety of spraying systems are commercially available. Standard spraying systems regulate the amount of product to be applied to a field by diluting the product in a carrier fluid and then controlling system pressure such that the volume of the product/carrier fluid combination sprayed varies with the speed of the application vehicle. As long as the application vehicle maintains a relatively constant speed, these systems do an adequate job of controlling application of the product. However, under conditions of varying vehicle speed (e.g. applications on undulating land), it is difficult to achieve the large pressure changes required to accommodate abrupt changes in vehicle speed and the associated quick adjustments to rate of fluid application.
An alternative approach to standard spraying is to directly inject the concentrated product into a constant flow of carrier. Various systems for direct injection spraying are described in "Injection Closed System . Sprayers", written by A.J. Landers and published in 1989 in Pesticide Outlook. Direct injection spraying systems reduce exposure of the operator to the product, reduce overdosing and underdosing in product application, increase flexibility of applications by permitting spot treatment and adjustment of the dosages, and increase accuracy of metering.
At the same time, agricultural controllers have evolved to better control the operation of farm implements used in planting and spraying systems. Among the first controllers were hard-wired devices such as that disclosed in Allman et al. U.S. Pat. No. 4,093,107 for use in a spraying system. Spraying systems with this type of controller required a high level of sophistication on the part of the user and were difficult to adapt to changes in system parameters such as boom width.
Other controllers, such as those disclosed in Lestradet U.S. Pat. No. 4,023,020, Kays U.S. Pat. No. 4,220,998 and McGlynn U.S. Pat. No. 4,013,875, achieved greater flexibility by teaching the use of electronic computer elements for the control and monitoring of farm implements.
Recent controllers, such as that disclosed in Bachman et al. U.S. Pat. No. 4,803,626 which is hereby incorporated by reference, present an even more flexible controller system which is programmed to accept a variety of different types of implement controls and sensors. Flowmeters, valves and other equipment are no longer limited to the original equipment. Sprayers can be fabricated from a wide variety of components, including components manufactured by rival companies.
A system like the one described by Bachman et al. demonstrates the improved flexibility possible through the use of microcontrollers and programmable I/O. However the Bachman system provides no paths for communicating the status of those components or the results of the spraying operation to other devices. In addition, the wiring between the controller and the remainder of the system is not readily adaptable for expansion to include control of other devices.
Current agricultural control systems still require a separate planting controller for planting systems and a spraying controller for spraying systems. There are no mechanisms for the sharing of information gathered during each operation or the incorporation of shared information to improve implement control. The separation of the two functions means that either individual passes must be made through a field for planting, fertilizing and pesticide application or the application vehicle must be cluttered with a multitude of incompatible controller equipment, each with its own unique calibration, maintenance and operational needs.
Furthermore, separate cables must be routed from each system component to its associated controller. The result is a jumble of wiring and reduced system reliability. Sensors that are to be used by more than one system must by necessity be connected to each system. As the types of sensors used in spraying and planting increase in number and the sensors become more complex, the information they generate could be profitably shared by many applications, but cannot be shared without further increasing the complexity, and potential misconnection and other wiring problems, of wiring.
An integrated system of planting and spraying which allows for sharing of data between each controller in the system and minimizes the amount of wiring in the system would be beneficial.